Glasgow Warriors: Greg Peterson & Scott Cummings out for six months after surgery

Peterson (left) and Cummings (right) are rehabilitating from shoulder injuries

Glasgow locks Greg Peterson and Scott Cummings will be out for up to six months after both had shoulder surgery.

Scotland Under-20 cap Cummings, 19, was injured in pre-season and United States second row Peterson came off in the recent defeat by Ulster.

Namibian Tjiuee Uanivi is also undergoing investigation on a shoulder injury, while a fourth lock, Tim Swinson (ribs), is also sidelined.

It leaves co-captain Jonny Gray as Glasgow's only fit frontline lock.

With Gray rested for Saturday's Pro12 trip to face Zebre in Italy, Rob Harley - a specialist blind-side flanker - and Robert McAlpine, making his first start after a debut off the bench against Dragons last week, form the second-row partnership in Parma, with Scottish Academy lock Callum Hunter-Hill primed for a possible debut off the bench.

Scotland centres Mark Bennett (head) and Alex Dunbar (back/knee), plus scrum-half Henry Pyrgos (neck), have joined a Warriors injury list currently totalling 13 players.